Traditionally, granule of TCM or herbal medicine is prepared from TCM, herbal medicine or their extract by dry granulating method or wet granulating method to produce granular material with certain particle diameter. When administered, it is taken after being mixed with water or swallowed. Due to the high viscosity of the extractum of TCM or herbal medicine, such shortcomings exist in most granules prepared by conventional granulating method as low drug loading, unsatisfactory appearance, poor taste and high moisture absorption, etc. By the current popular fluidized-bed granulating technique, various carriers are placed in the container alone or in combination with pharmaceutical powder, and air at proper temperature is insufflated through the sieve plate from the bottom of bed to well mix the material in fluid condition, then solution of binder is evenly sprayed into. Accordingly, the powder begins to agglomerate to obtain granule. After repeated spraying and drying, granules with desired particle diameter are produced, then stopping spraying, and continuing to dry. This process can decrease the amount of carrier from the conventional 80 wt % to less than 50 wt % and also decrease single dose of the granule from 10 g to 3-5 g. However, this process can neither solve problems caused by high viscosity of extract of TCM or herbal medicine, nor further decrease the amount of carrier. Therefore, these disadvantages such as high single dose and poor compliance of patients exist in the granule prepared by the process. Also, these granules are unsuitable to be prepared into solid preparation such as capsules etc. In addition, the granules prepared by this method are porous and irregular in shape, and commonly has shortcoming of moisture absorption, accordingly it is inconvenient to store these granules. Due to the high specific surface area, such granules are unsuitable to be coated.
Currently, there are also researches to produce micro-pills with a particle diameter of 700-1500 μm using extract of TCM or herbal medicine by fluidized-bed granulation process. However, according to this process, medicines are made into dry powder, which is added while spraying water or other liquid mixture as binder to produce micro-pills. The micro-pills prepared by this process commonly have a dissolution time of 40 minutes. In addition, the process is complex, high-cost and high-consuming with many affecting factors (for example, it can not be performed in the condition of high air-humidity).
Additionally, extrusion-rounding method or extrusion-spheronization method is also used to produce micro-pills or spherical granules in the pharmaceutical field. Products by this method consume a large amount of carrier with a drug loading of less than 25% and a dissolution time of more than 30 minutes.
In the art of dosage form, fluidized-bed granulation processes by bottom spraying or side spraying have been used to produce micro-pills or spherical granules of chemical medicine. Most of them are used to develop sustaining-release preparations. So, the products prepared by the processes are usually sustaining-released or controlled-released instead of rapid released.
The rapid release and rapid onset of therapeutic effect of TCM are important aspects of TCM modernization. The granules of TCM or herbal medicine provided in the present invention have the property of rapid dissolution.